The present invention is directed, in general, to television broadcast systems and, more specifically, to a system and method for receiving digital and analog television broadcasts.
When television was first introduced, radio frequency (RF) analog terrestrial television broadcast was the only method of sending and receiving television broadcasts. Existing television sets have an RF Network Interface Module (NIM) for receiving an analog signal in addition to baseband signal processing circuitry. Over the years, this basic architecture has remained unchanged. However, with the relatively new introduction of digital television broadcasts, various television broadcast services have become more effective over terrestrial, cable and switched network channels.
Conventional digital television (DTV) broadcast receivers utilize, in part, an analog tuner for conventional analog television broadcast reception. A digital tuner and Vestigial Side Band (VSB) modulator are key components, in digital television, for receiving and demodulating broadcast digital signals. However, VSB is considered to be an emerging/developing technology and there are proposals to change or improve the Advanced Television Systems Committee (ATSC) standard to use a different transmission technology. Digital television (DTV) includes components for analog reception because, currently, the majority of all television broadcasts are analog broadcasts. However, the Federal Communication Commission (FCC) has issued directives that require broadcasting affiliates of the major networks to complete the transition to DTV between the years 2003 and 2006.
Currently many digital cable service providers and consumers rely on set top boxes (STBs) to convert digital video broadcast signals for analog television sets. In addition to network or cable broadcast signals, digital video signals may also be received from a Compact Disk Read Only Memory (CD-ROM) player, or from a Digital Video Disk (DVD) player. A STB may receive and process both a digital and an analog video signal. If the received signal is digital, the STB demodulates the signal and passes the converted signal to the television receiver via an IEEE-1394 bus (i.e., a bus using the IEEE standard 1394-1995). If the received broadcast signal is analog, the signal is passed directly to the analog television receiver.
In low-end set top boxes, analog signals are the only signals that may be passed to the analog television receiver. In high-end set top boxes, digital signals are processed by the set top box (STB) and analog signals may be passed to the receiver via the progressive scan (2fH) analog component video connectors. Additionally, digital signals may be transmitted over cable television through the STB utilizing Moving Pictures Experts Group (MPEG) format and graphic overlays. A digital video signal may also be transmitted through the STB via an IEEE-1394 bus from a digital camcorder (a combination camera and video recorder), digital Video Cassette Recorder (D-VCR), Digital Video Disk (DVD), and other similar types of equipment.
Current TV/DTV architecture requires RF input and channel decoding functions in the DTV xe2x80x9cfront endxe2x80x9d (e.g., VSB modulation and Quadrature Amplitude Modulation (QAM)) in order to receive and display audio/video (A/V) programs. Additionally, as new broadcast services are added, additional RF inputs are usually required, which adds to the cost of a television receiver.
There is therefore a need in the art for eliminating RF inputs in a television receiver. There is a need in the art to retain the capability of receiving analog signals. There is also a need in the art to accommodate new broadcast services without adding RF inputs. Further, there is also a need in the art to reduce the cost of digital television receivers.
To address the above-discussed deficiencies of the prior art, it is a primary object of the present invention to provide, for use in a digital television receiver, a system for receiving analog and digital video signals without RF inputs.
It is a further object of the present invention to provide a system that will process and display analog broadcast television audio/video signals.
It is another object of the present invention to provide a system that will process and display broadcast digital television signals and digital outputs from digital audio/video units such as digital VCRs, digital video camcorders, digital outputs from set top boxes and similar types of equipment.
It is also an object of the present invention to provide a system comprising a baseband digital television that is capable of operating as a universal multi-standard digital television.
It is another object of the present invention to provide a system comprising a baseband digital television that is capable of supporting both the ATSC standard and the DVB standard with respect to an MPEG transport stream input.
It is also an object of the present invention to provide a system comprising a baseband digital television that will minimize the likelihood of obsolescence.
The system comprises a digital network interface coupled to a digital main board for receiving baseband audio and video digital signals and a digital video decoder coupled to the digital network interface for decoding audio and video digital signals from the digital network interface. The digital video decoder sends the decoded signals to the digital main board. The system also comprises an analog television chassis having an input that is capable of receiving audio and video analog signals. The digital main board digitizes the analog signals into a digital transport stream prior to processing.
According to an advantageous embodiment of the present invention, the digital network interface comprises an input capable of receiving audio and video digital signals from a digital signal playback device.
According to another advantageous embodiment of the present invention, a graphics overlay signal generator coupled to the digital main board is capable of adding at least one digital video signal to digital video signals within the digital main board.
According to yet another advantageous embodiment of the present invention, the analog television chassis comprises an input capable of receiving audio and video analog signals.
According to still another advantageous embodiment of the present invention, the digital network interface comprises an IEEE 1394 bus.
According to an additional advantageous embodiment of the present invention, the analog television chassis is capable of receiving audio and video analog signals having a 2fH format.
The foregoing has outlined rather broadly the features and technical advantages of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.
Before undertaking the DETAILED DESCRIPTION, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms xe2x80x9cincludexe2x80x9d and xe2x80x9ccomprise,xe2x80x9d as well as derivatives thereof, mean inclusion without limitation; the term xe2x80x9cor,xe2x80x9d is inclusive, meaning and/or; the phrases xe2x80x9cassociated withxe2x80x9d and xe2x80x9cassociated therewith,xe2x80x9d as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term xe2x80x9ccontrollerxe2x80x9d means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. In particular, a controller may comprise one or more data processors, and associated input/output devices and memory, that execute one or more application programs and/or an operating system program. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.